During recent testing at Peterbilt's Texas headquarters, the Delphi SOFC provided power for the Model 386's electrical system and air conditioning and maintained the truck's batteries, while the Model 386's diesel engine was turned off.

This demonstration, held in June, leveraged development supported by the U.S. Department of Energy's Energy Efficiency and Renewable Energy and Fossil Energy Solid State Energy's Conversion Alliance program.

Delphi's SOFC converts chemical energy in conventional fuels directly into useful electrical power without combustion. A SOFC operates quietly and at a higher efficiency level than traditional internal combustion engines. By limiting idling time and running a SOFC instead of the main engine, emissions are reduced, noise is nearly eliminated, and operators realize significant fuel savings.

The technology will have the capability of using a variety of fuels, including natural gas, diesel, bio-diesel, propane, gasoline, coal-derived fuel and military logistics fuel. In addition to its fuel flexibility, the SOFC will be compact in size.

The Peterbilt/Delphi test replicated a typical trucker's day to evaluate the real-world usefulness and capacity of the SOFC:

• To begin, the SOFC APU was brought to operating temperature with the truck's main engine running. This simulated starting the SOFC APU during normal, on-road driving conditions.• Once the SOFC APU was at temperature and available to provide power, the Model 386's main engine was turned off, simulating the beginning of a rest period.• During the rest period, the SOFC APU powered the 386's electrical loads, including the electric air-conditioner, radio, citizens band radio, and lights. It also charged the truck's battery.• After 10 hours (representing running overnight) the Model 386's main engine was restarted to simulate the driver beginning his drive for the next day. • Throughout the test, the SOFC APU provided an average of 800 watts of electricity to the Peterbilt Model 386.

"The SOFC system provides a technologically-advanced solution to meet anti-idle requirements while surpassing expectations for reduced emissions, noise and fuel consumption," said Landon Sproull, Peterbilt chief engineer. "This system has the potential to revolutionize future APUs by setting new benchmarks for performance and ease of operation with no adverse effects on the environment."